Abstract This study investigated the physicochemical properties of milk protein isolate (MPI) suspensions when sodium caseinate (NaCAS) was incorporated by wet- or dry-blending. The studied MPI had a solubility of only 89.6% when it was the sole contributor to total protein. In dry-blended samples, solubility was increased to a maximum of 97.5% when NaCAS contributed 15% to total protein. High volumes of micellar casein (73.2%) and low volumes of primary powder particles (27.8%) were measured in dry-blended systems with 15.0% NaCAS addition, corresponding to high suspension stability. Wet blending only improved the solubility slightly to 92.3% and resulted in a large volume of primary powder particles. Differences in physicochemical properties between dry and wet-blending might be attributed to the strong tendency of NaCAS to promote dissociation of casein micelles under dry-blending conditions. The results indicate the dry-blending approach represents an effective strategy for obtaining MPI/NaCAS suspensions with high solubility.

中文翻译：

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通过添加酪蛋白酸钠提高乳蛋白分离物的溶解度：湿法和干法混合方法的比较

摘要 本研究调查了通过湿法或干法掺入酪蛋白酸钠 (NaCAS) 时乳分离蛋白 (MPI) 悬浮液的理化性质。当它是总蛋白质的唯一贡献者时，所研究的 MPI 的溶解度仅为 89.6%。在干混样品中，当 NaCAS 占总蛋白质的 15% 时，溶解度增加到最大 97.5%。在添加 15.0% NaCAS 的干混系统中测量到大量的胶束酪蛋白 (73.2%) 和少量的初级粉末颗粒 (27.8%)，对应于高悬浮稳定性。湿法混合仅将溶解度略微提高至 92.3%，并导致大量初级粉末颗粒。干混和湿混之间物理化学性质的差异可能归因于 NaCAS 在干混条件下促进酪蛋白胶束解离的强烈趋势。结果表明干混方法代表了获得具有高溶解度的 MPI/NaCAS 悬浮液的有效策略。